His ship The Endurance, fought through thick ice toward the continent. While deep in the pack of the Weddell Sea, the ship got stuck in the crushing ice. This was on January 8th.

It became clear that that the crew would be stuck until rescue, but no one at the time had any idea just how long they would have to wait.

They camped on the ice beside the crushed ship. The temp ranged from 30's to a low of -21 degrees Fahrenheit. Their clothing was inadequate and the sleeping bags were often moist. They warmed themselves with broken timber and when food rations ran out, they began eating wildlife, mostly penguins and seals.

By March 1916 they were forced to shoot their dogs for food.

The men began an arduous journey through the ice in search of land and ended up on Elephant Island. Many of the men lost their lives and some went insane. In all there were 27 men left. Shakleton realized they were still too far away to be rescued so he, and five of his strongest men, set out on the largest lifeboat for an 800 mile trek to South Georgia Island.

They would reach the island on May 19th. Their extremities were frostbiten and numb but they set out on foot for the whaling stations, 22 miles away. It was a 36 hour march but they made it and secured a rescue ship.

Unfortunately the ice was still too thick to attempt a rescue. Months went by, and failed rescue attempts increased. Finally in October of 1915, the men were rescued. All of the remaining men on Elephant Island were still alive and were awarded the Polar Medal upon their return home. Shackleton's feat of survival was overshadowed by WWI and the death of Robert F. Scott.

Sources: American Museum of Natural History, National Geographic, The Endurance by Alfred Lansing